U.S. patent application number 14/560331 was filed with the patent office on 2015-06-25 for apparatus and method for aligning optical axes of lenses and assembling camera module.
The applicant listed for this patent is Isolution Co., Ltd.. Invention is credited to Sung Kwan KANG.
Application Number | 20150174715 14/560331 |
Document ID | / |
Family ID | 53399053 |
Filed Date | 2015-06-25 |
United States Patent
Application |
20150174715 |
Kind Code |
A1 |
KANG; Sung Kwan |
June 25, 2015 |
APPARATUS AND METHOD FOR ALIGNING OPTICAL AXES OF LENSES AND
ASSEMBLING CAMERA MODULE
Abstract
Provided are an apparatus and method of aligning optical axes of
lenses and assembling a camera module that are capable of adjusting
the optical axes of the lenses. The apparatus for aligning the
optical axes of the lenses and assembling the camera module
includes a support block to support a substrate at which an image
sensor is installed, a displacement sensor to measure a tilted
state of the image sensor, a fastener to fasten or loosen fastening
components to couple a lens holder to the substrate, and a
controller to control a fastening level of the lens holder by the
fastener to correct a tilted state according to a measurement
result of the displacement sensor. The optical axis of the lens can
be rapidly and precisely adjusted and assembled by use of the above
described apparatus and method.
Inventors: |
KANG; Sung Kwan; (Yongin-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Isolution Co., Ltd. |
Cheonan-si |
|
KR |
|
|
Family ID: |
53399053 |
Appl. No.: |
14/560331 |
Filed: |
December 4, 2014 |
Current U.S.
Class: |
29/407.04 ;
29/407.1; 29/705; 29/714 |
Current CPC
Class: |
Y10T 29/53022 20150115;
G03B 43/00 20130101; Y10T 29/53061 20150115; B23P 19/105 20130101;
Y10T 29/4978 20150115; B23P 19/04 20130101; B23P 21/00 20130101;
Y10T 29/49769 20150115 |
International
Class: |
B23P 19/10 20060101
B23P019/10; B23P 19/04 20060101 B23P019/04; B23P 21/00 20060101
B23P021/00; G03B 13/32 20060101 G03B013/32 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2013 |
KR |
10-2013-0159153 |
Jun 9, 2014 |
KR |
10-2014-0069736 |
Jun 11, 2014 |
KR |
10-2014-0070555 |
Claims
1. An apparatus for aligning optical axes of lenses and assembling
a camera module, the apparatus comprising: a support block
configured to support a substrate on which an image sensor is
installed; a displacement sensor configured to detect a tilted
state of the image sensor to generate sensor tilt information; a
lens holder coupled with the substrate by means of fastening
components; a fastener driven to tighten or loosen the fastening
components; and a controller configured to control the fastener,
wherein the controller is controlled according to the sensor tilt
information to control the fastener to fasten or loosen the
fastening components with different fastening levels to correct the
tilted state of the image sensor.
2. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 1, further
comprising a dispenser configured to apply an adhesive agent to one
surface of the lens holder to attach a lens barrel on which the
lens is mounted to the lens holder.
3. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 2, further
comprising a lens clamper configured to clamp and move the lens
barrel on an adhesion surface of the lens holder to which the
adhesive agent is applied.
4. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 2, further
comprising a UV radiator configured to radiate an ultraviolet ray
to the adhesive agent and cure the adhesive agent.
5. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 2, further
comprising an LED illuminator configured to provide uniform
illumination to inspect the lens with naked eyes.
6. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 5, wherein the LED
illuminator enables determination of whether a surface defect of
the lens is present and inspection of the optical axis.
7. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 2, further
comprising a test chart system having a test pattern detected by
the image sensor through the lens.
8. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 7, further
comprising a collimator lens disposed between the lens and the test
chart system to reduce a focal distance of the lens.
9. The apparatus for aligning the optical axes of the lenses and
assembling the camera module according to claim 1, wherein the
fastening components are at least two bolts, and the fastener is a
bolt fastener for tightening or loosening the at least two
bolts.
10. A method of aligning optical axes of lenses and assembling a
camera module, the method comprising: setting a substrate, at which
an image sensor is installed and to which a lens holder is
fastened, to a support block, wherein an active region of the image
sensor is exposed through a holder hole of the lens holder;
measuring a plurality of points of the active region of the image
sensor exposed through the holder hole to generate sensor tilting
information to correct tilting of the image sensor, wherein a
controller controls the support block according to the sensor
tilting information; and inserting a lens barrel at which the lens
is installed into the lens holder to which an adhesive agent is
applied.
11. The method of aligning the optical axes of the lenses and
assembling the camera module according to claim 10, further
comprising aligning a center of the lens to a reference point of
the image sensor, wherein the controller controls the lens barrel
according to a lens image which is an image of a test chart
detected by the image sensor through the lens.
12. The method of aligning the optical axes of the lenses and
assembling the camera module according to claim 10, further
comprising matching a reference point of a test chart and a
reference point of the image sensor, wherein the controller is
driven to shift the support block or the test chart according to a
vision image which is an image of the image sensor checked by a
vision camera.
13. The method of aligning the optical axes of the lenses and
assembling the camera module according to claim 12, wherein the
reference point of the image sensor is a center point of the image
sensor, and the reference point of the test chart is a center point
of the test chart.
14. A method of aligning optical axes of lenses and assembling a
camera module, the method comprising: heating the camera module,
wherein the camera module comprises a substrate at which an image
sensor is installed, a lens barrel at which a lens is installed,
and a lens holder coupled between the substrate and the lens
barrel; applying an adhesive agent between the lens barrel and the
lens holder; setting the camera module to a support block;
measuring a plurality of points on a section of the lens barrel to
generate barrel tilting information; and controlling the support
block according to the barrel tilting information.
15. The method of aligning the optical axes of the lenses and
assembling the camera module according to claim 14, further
comprising determining whether an optical axis of the camera module
is good or bad using a determination image, wherein the
determination image is an image of a test chart detected by the
image sensor.
16. The method of aligning the optical axes of the lenses and
assembling the camera module according to claim 14, further
comprising shifting the support block or the test chart according
to a heating vision image in order to match a reference point of
the test chart and a reference point of the lens, wherein the
heating vision image is an image of the lens checked by a vision
camera after heating the adhesive agent.
17. The method of aligning the optical axes of the lenses and
assembling the camera module according to claim 16, wherein the
reference point of the lens is a center point of the lens, and the
reference point of the test chart is a center point of the test
chart.
18. The method of aligning the optical axes of the lenses and
assembling the camera module according to claim 14, wherein the
plurality of the points of the lens barrel are measured by a
confocal displacement sensor.
19. A method of aligning optical axes of lenses and assembling a
camera module, the method comprising: measuring a plurality of
points on a substrate of the camera module to generate substrate
tilting information, wherein the camera module includes the
substrate at which an image sensor is installed, a lens barrel at
which a lens is installed, and a lens holder coupled between the
substrate and the lens barrel, and the lens barrel is coupled to
the lens holder through an adhesive agent; heating the camera
module; setting the camera module to a support block; driving a
controller to control the support block according to the substrate
tilting information; and causing the controller to determine
whether tan optical axis of the camera module is good or bad using
a determination image, wherein the determination image is an image
of a test chart detected by the image sensor.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus and method of
assembling a camera module for monitoring front and rear sides or
automatic driving of a vehicle, and more particularly, to an
apparatus and method of aligning optical axes of lenses installed
in a camera module and assembling the camera module.
[0003] 2. Discussion of Related Art
[0004] In recent automobile technologies, cameras are mounted in a
vehicle to guide parking or monitor surroundings of the vehicle.
Demand of mounting cameras in a vehicle increases for the purposes
of, for example, monitoring performance of automatic driving
function such as lane maintaining, road sign recognition, or the
like.
[0005] In general, a camera mounted in a vehicle is supplied as a
module type in which various parts such as an image sensor, a lens,
and so on, are integrally assembled. In case that optical axes of
the lens or the image sensor cannot be precisely aligned, the
camera cannot properly perform the intended functions such as
monitoring performances of a vehicle.
[0006] Accordingly, in order to implement proper performance of a
camera module, especially a high performance camera module, with
high reliability, the optical axes of the lenses should be
precisely adjusted upon assembly of the camera module. Thus, needed
are an apparatus and method of assembling a camera module with
capability of precise adjustment and alignment of optical axes of
the lenses.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to an apparatus and method
of aligning optical axes of lenses and assembling a camera module,
which are improved to efficiently assemble the camera module while
precisely adjusting the optical axes of the lenses.
[0008] According to an aspect of the present invention, an
apparatus for aligning optical axes of lenses and assembling a
camera module includes a support block configured to support a
substrate on which an image sensor is installed; a displacement
sensor configured to detect a tilted state of the image sensor to
generate sensor tilt information; a lens holder coupled with the
substrate by means of fastening components; a fastener driven to
tighten or loosen the fastening components; and a controller
configured to control the fastener. The controller is controlled
according to the sensor tilt information to control the fastener to
fasten or loosen the fastening components with different fastening
levels while controlling an axis of the support block in order to
correct the tilted state of the image sensor.
[0009] According to other aspect of the present invention, a method
of aligning optical axes of lenses and assembling a camera module
includes a support block setting step of setting a substrate, at
which an image sensor is installed and to which a lens holder is
fastened, to a support block, wherein an active region of the image
sensor is exposed through a holder hole the lens holder; a sensor
tilting correction step of measuring a plurality of points of the
active region of the image sensor exposed through the holder hole
using a displacement sensor to generate sensor tilt information in
order to correct tilting of the image sensor, wherein a controller
controls the support block according to the sensor tilt
information; a lens barrel insertion step of inserting a lens
barrel at which the lens is installed into the lens holder to which
an adhesive agent is applied, after the tilting correction step is
performed; and a lens barrel control step of aligning a center of
the lens to a reference point of the image sensor after the lens
barrel insertion step is performed, wherein the controller controls
the lens barrel according to a lens image, and the lens image is an
image of the test chart detected by the image sensor through the
lens.
[0010] According to another aspect of the present invention, a
method of aligning optical axes of lenses and assembling a camera
module includes a module heating step of heating the camera module,
wherein the camera module comprises a substrate at which an image
sensor is installed, a lens barrel at which a lens is installed,
and a lens holder coupled between the substrate and the lens
barrel; applying an adhesive agent between the lens barrel and the
lens holder; a support block setting step of setting the heated
camera module to a support block; a barrel tilting correction step
of measuring a plurality of points on an end section of the lens
barrel of the heated camera module using a displacement sensor to
generate barrel tilting information, wherein a controller controls
the support block according to the barrel tilting information; and
a determination step of causing the controller to determine whether
the optical axis of the camera module is good or bad through a
determination image after the barrel tilting correction step is
performed, wherein the determination image is an image of a test
chart detected by the image sensor.
[0011] According to another aspect of the present invention, a
camera module manufactured by the method according to the method is
provided.
[0012] In the apparatus and method of aligning the optical axes of
the lenses and assembling the camera module having the
above-mentioned configuration, the lenses can be assembled while
rapidly and precisely adjusting the optical axes so that the high
performance camera module can be efficiently implemented.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other objects, features and advantages of the
present invention will become more apparent to those of ordinary
skill in the art by describing in detail exemplary embodiments
thereof with reference to the accompanying drawings, in which:
[0014] FIG. 1 is an exploded perspective view showing a structure
of a camera module adjusted by an apparatus for aligning optical
axes of lenses and assembling a camera module according to the
present invention;
[0015] FIGS. 2A And 2B are views showing the apparatus for aligning
the optical axes of the lenses and assembling the camera module of
the present invention;
[0016] FIG. 3 is a view showing a process of measuring a tilted
state of an image sensor using a displacement sensor of the
apparatus for aligning the optical axes of the lenses and
assembling the camera module of the present invention;
[0017] FIG. 4 is a cross-sectional view of the camera module shown
in FIG. 1;
[0018] FIG. 5 is a view for describing a process of lens barrel
tilting correction by means of the apparatus for aligning the
optical axes of the lenses and assembling the camera module of the
present invention;
[0019] FIG. 6 is a view for describing a process of measuring and
matching a reference point of an image sensor and a reference point
of a test chart using a vision camera for the lens barrel tilting
correction;
[0020] FIG. 7 is a view for describing a process of matching a
center point of the lens and the reference point of the image
sensor installed at a lens barrel for the lens barrel tilting
correction;
[0021] FIG. 8 is a flowchart showing a method of aligning optical
axes of lenses and assembling a module of the present invention to
perform the lens barrel tilting correction;
[0022] FIG. 9 is a view for describing a process of adhesive agent
curing tilting correction by means of the apparatus for aligning
the optical axes of the lenses and assembling the camera module of
the present invention;
[0023] FIG. 10 is a view for describing a process of matching a
center point of the lens and a reference point of a test chart for
the adhesive agent curing tilting correction;
[0024] FIG. 11 is a view for describing a process of determining
whether a defect of the camera module is generated by measuring a
test chart using an image sensor for the adhesive agent curing
tilting correction;
[0025] FIG. 12 is a flowchart showing a method of aligning optical
axes of lenses and assembling a camera module according to an
embodiment of the present invention to perform the adhesive agent
curing tilting correction;
[0026] FIGS. 13A to 13D are views for describing a process of
installing a lens barrel to a lens holder; and
[0027] FIG. 14 is a flowchart showing a method of aligning optical
axes of lenses and assembling a camera module according to another
embodiment of the present invention to perform the adhesive agent
curing tilting correction.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0028] Exemplary embodiments of the present invention will be
described in detail below with reference to the accompanying
drawings. While the present invention is shown and described in
connection with exemplary embodiments thereof, it will be apparent
to those skilled in the art that various modifications can be made
without departing from the spirit and scope of the invention.
[0029] Hereinafter, embodiments of the present invention will be
described in detail with reference to the accompanying drawings.
However, specific structural and functional details disclosed
herein are merely representative for purposes of describing
exemplary embodiments of the present invention. It will be
understood that when an element is referred to as being on another
element, it can be directly on the other element or intervening
elements may be present therebetween. In contrast, when an element
is referred to as being "directly on" another element, there are no
intervening elements present. The terminology used herein is for
the purpose of describing particular embodiments only and is not
intended to be limiting of the invention. As used herein, the
singular forms "a", "an" and "the" are intended to include the
plural forms as well, unless the context clearly indicates
otherwise. It will be further understood that the terms "comprises"
and/or "comprising," or "includes" and/or "including" when used in
this specification, specify the presence of stated features,
regions, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, regions, integers, steps, operations, elements,
components, and/or groups thereof.
[0030] The present invention relates to an apparatus for aligning
optical axes of lenses and assembling a camera module to assemble a
camera module 10 as shown in FIG. 1, and a method of aligning
optical axes of lenses using the same.
[0031] The camera module 10 includes a substrate 15 to which an
image sensor 14 is attached, a lens holder 13, and a lens barrel
11.
[0032] For example, the substrate 15 is wired to transmit signals,
data, information, and so on. The lens holder 13 is coupled with
the substrate 15. The lens barrel 11 on which a lens 12 is mounted
is coupled to the lens holder 13.
[0033] The lens can be focused on a precise position of the image
sensor 14 when the optical axes of the assembled camera module 10
are aligned well. In contrast, the lens may be focused on an
incorrect position when an error occurs in the alignment of the
optical axes.
[0034] The causes of generating the error in the optical axis
alignment may include the followings but not limited to.
[0035] A first cause is "image sensor attachment tilting" which can
be generated when the image sensor 14 is attached to the substrate
15 via a conductive adhesive agent.
[0036] A second cause is "`lens barrel coupling tilting" which can
be generated when the lens barrel 11 is coupled to the lens holder
13 fastened to the substrate 15 at which the image sensor 14 is
installed.
[0037] A third cause is "`adhesive agent curing tilting" which can
be generated when the adhesive agent between the lens holder 13 and
the lens barrel 11 is cured through heating.
[0038] Exemplary embodiments of the apparatus for aligning the
optical axes of the lenses and assembling the camera module will be
described with reference to the relevant drawings.
[0039] FIGS. 2A and 2B show exemplary embodiments of configuration
of the apparatus for aligning the optical axes of the lens. Here,
FIG. 2A shows one exemplary embodiment where a fisheye lens is
mounted on the camera module 10, and FIG. 2B shows another
exemplary embodiment where a normal lens is mounted.
[0040] Reference numeral 100 designates a test chart system
test-photographed by the image sensor 14. A test chart having a
test pattern detected by the image sensor 14 is installed at the
test chart system 100.
[0041] Reference numeral 200 designates a displacement sensor
configured to detect a tilted state of a subject to generate
various tilt information. The displacement sensor 200 can detect a
tilted state of the camera module 10, the image sensor 14, an end
section of the lens barrel 11, or the like, to generate tilt
information. For example, the displacement sensor 200 can be
implemented with a non-contact sensor or a confocal displacement
sensor configured to precisely measure displacement of the subject
using a wavelength range of light. In other instances, the
displacement sensor 200 may be implemented with a two-dimensional
or three-dimensional displacement sensor configured to measure the
displacement while moving along the entire line or surface at a
predetermined speed.
[0042] Reference numeral 300 designates a lens clamper configured
to clamp the lens barrel 11 (see FIG. 1) inserted and coupled into
the lens holder 13 and adjust the position while moving the lens
barrel 11 on a coupling surface of the lens holder 13 by a fine
gap. Reference numeral 210 designates a vision camera configured to
a horizontal shift level of the image sensor 14.
[0043] Reference numeral 400 designates a fastener which is driven
to tighten or loosen fastening components by means of which the
lens holder 13 is coupled with the substrate 15. In this
embodiment, for example, a bolt fastener 400 is employed to tighten
or loosen bolts which are employed as the fastening components.
[0044] Reference numeral 500 designates a dispenser configured to
apply an adhesive agent to one surface of the lens holder 13 to
couple the lens barrel 11 to the lens holder 13. Reference numeral
510 designates an UV radiator configured to radiate an ultraviolet
ray to the adhesive agent to cure the adhesive agent.
[0045] Reference numeral 600 designates an LED illuminator
configured to illuminate the camera module 10 mounted on a support
block 800 to easily check contaminations or cracks of the lens 12
with naked eyes. In addition, a test of shading and an optical axis
can be observed with naked eyes by use of the LED illuminator
600.
[0046] Reference numeral 700 designates a collimator lens
configured to reduce a focal distance of the lens 12 to be focused
to a pattern of a test chart system installed near the camera
module 10.
[0047] An assembled object is mounted on the support block 800.
Tilting of the support block 800 can be adjusted.
[0048] Reference numeral 900 designates a controller configured to
control the entire components.
[0049] A method of aligning optical axes of lenses and assembling a
camera module to correct three kinds of tilting that causes
deviation of the optical axes using the apparatus for aligning the
optical axes of the lenses and assembling the camera module of the
present invention will be sequentially described.
Image Sensor Attachment Tilting Correction
[0050] When the image sensor attachment tilting is generated, the
optical axis with reference to a center of the image sensor 14 is
tilted, so that a center of the lens 12 is deviated from the center
of the image sensor 14 when the lens holder 13 and the lens barrel
11 are installed with reference to a vertical line of the
center.
[0051] An exemplary embodiment of the apparatus for aligning the
optical axes of the lenses and assembling the camera module to
correct the image sensor attachment tilting will be described below
with reference to the relevant drawings.
[0052] The support block 800 supports the substrate 15 to which the
image sensor 14 is attached. The displacement sensor 200 detects
the tilted state of the image sensor 14 to generate sensor tilt
information. The lens holder 13 is coupled with the substrate 15 by
means of fastening components. In this embodiment, for example, the
lens holder 13 is fastened to the substrate 15 by at least two
bolts 16. The bolt fastener 400 is driven to fasten the at least
two bolts 16 to fasten the lens holder 13 to the substrate 15. The
controller 900 controls the bolt fastener 400. Thereby, the support
block 800 can adjust the tilting.
[0053] In other words, the substrate 15 to which the image sensor
14 is attached is placed on the support block 800. The tilted state
of the image sensor 14 is detected to generate the sensor tilt
information by the displacement sensor 200. The controller 900
performs in accordance with the sensor tilt information to correct
the tilted state of the image sensor 14, and controls the bolt
fastener 400. The controller 900 may also perform controlling an
axis of the support block 800 as well as the controlling of the
bolt fastener 400. Thus, the lens holder 13 is fastened to or
loosened from the substrate 15 accordingly.
[0054] A process of aligning the optical axes using the apparatus
for aligning the optical axes of the lenses and assembling the
camera module of the present invention is described below.
[0055] The substrate 15 to which the image sensor 14 is attached is
mounted on the support block 800. The substrate 15 may be mounted
in an automatic or manual manner. Here, a center of the image
sensor 14 of the substrate 15 may be slightly tilted, and the
tilted state is measured by the displacement sensor 200.
[0056] As shown in FIG. 3, the displacement sensor 200 moves above
the support block 800 to measure flatness characteristics of
multiple points (for example, five or more) of the image sensor 14,
and the controller 900 recognizes the tilted state of the image
sensor 14 from the measurement information.
[0057] When the tilted state of the image sensor 14 is recognized,
a process of fastening/loosening the lens holder 13 is performed in
consideration of the tilted state. The controller 900 controls the
bolt fastener 400 to appropriately fasten or loosen the bolts 16.
The controller 900 may control the bolt fastener 400 while
adjusting the tilting through control of the axis of the support
block 800 according to the sensor tilt information.
[0058] As shown in FIG. 4, the bolts 16 are disposed at least two
places, and fastening levels of the bolts 16 are varied to correct
the tilted state of the image sensor 14. In other words, when the
fastening levels of the bolts 16 are varied, gaps between the lens
holder 13 and the substrate 15 may be different at different areas
such as a relatively more strongly fastened area and a relatively
less strongly fastened area. As a result, the tilted state of the
optical axis can be corrected when the fastening level is adjusted
by reflecting the tilted state of the image sensor 14 measured by
the displacement sensor 200.
[0059] The above description was made with reference to cross
section illustration of FIG. 4, which is a schematic illustration
of an idealized embodiment of the present invention. As such,
variations from the shapes of the illustration as a result, for
example, of manufacturing techniques and/or tolerances, are to be
expected. Thus, any embodiment of the present invention should not
be construed as limited to the particular shapes illustrated herein
but is to include deviations in shapes.
Lens Barrel Coupling Tilting Correction Compensation
[0060] Correcting the lens barrel coupling tilting by means of the
apparatus for aligning the optical axes of the lenses and
assembling the camera module of the present invention will be
described below.
[0061] Here, the support block 800 can adjust tilting, rotation and
shift. The lens holder 13 is fastened to the substrate 15 such that
an active region 14a of the image sensor 14 is exposed through a
holder hole 13a.
[0062] As shown in FIG. 5, the displacement sensor 200 detects the
tilted state of the image sensor 14 installed at the substrate 15
to generate the sensor tilt information.
[0063] The displacement sensor 200 measures displacement of a
plurality of points 14b on the active region 14a actually imaged by
the image sensor 14 to detect the tilted state of the image sensor
14.
[0064] The controller 900 is driven to control the support block
800, and ultimately tilt the image sensor 14 according to the
sensor tilt information to correct the tilted state of the image
sensor 14.
[0065] As shown in FIG. 6, the vision camera 210 checks a vision
image through the holder hole 13a of the lens holder 13. Here, the
vision image is an image of the image sensor 14.
[0066] In this case, the controller 900 is driven to shift the
support block 800 (ultimately, the image sensor 14) or a test chart
110 according to the vision image checked by the vision camera 210
to match a reference point P14 of the image sensor 14 and a
reference point P110 of the test chart 110.
[0067] The reference point P14 of the image sensor 14 is a center
point of the image sensor 14, and the reference point P110 of the
test chart 110 is a center point of the test chart 110.
[0068] The lens clamper 300 clamps and moves the lens barrel 11 at
which the lens 12 is installed. The lens clamper 300 may be
controlled by the controller 900.
[0069] As shown in FIG. 7, in a state that the lens barrel 11 is
fastened to the lens holder 13, a lens image serving as an image of
the test chart 110 is detected by the image sensor 14 through the
lens 12.
[0070] In this case, the controller 900 is driven to control the
lens barrel 11 in accordance with the lens image to match a center
point of the lens 12 with the reference point P14 of the image
sensor 14.
[0071] FIG. 8 is a flowchart showing the method of aligning the
optical axes of the lenses and assembling the camera module
according to an embodiment of the present invention, especially, to
correct the lens barrel coupling tilting.
[0072] Referring to FIG. 8, the method of aligning the optical axes
of the lenses and assembling the camera module of the present
invention to correct the lens barrel coupling tilting includes a
support block setting step (S110), a tilting correction step
(S120), a reference alignment step (S130), a lens barrel insertion
step (S140), and a lens barrel control step (S150).
[0073] In the support block setting step (S110), the image sensor
14 is installed, and the substrate 15 to which the lens holder 13
is fastened is set to the support block 800. The lens holder 13 is
fastened to the substrate 15 such the active region 14a of the
image sensor 14 is exposed through the holder hole 13a. (referring
to FIG. 5)
[0074] In the sensor tilting correction step (S120), the plurality
of points 14b of the active region 14a of the image sensor 14 are
measured by the displacement sensor 200 to generate the sensor tilt
information. In order to correct the tilting of the image sensor
14, the controller 900 is driven to control the support block 800
according to the sensor tilt information.
[0075] In the reference alignment step S130, in order to match the
reference point P110 of the test chart 110 and the reference point
P14 of the image sensor 14, the controller 900 is controlled to
shift the support block 800 or the test chart 110 according to the
vision image. As mentioned above, the vision image is an image of
the image sensor 14 checked by the vision camera 210.
[0076] The reference point P14 of the image sensor 14 may be the
center point of the image sensor 14, and the reference point P110
of the test chart 110 may be the center point of the test chart
110.
[0077] In the lens barrel insertion step (S140), the lens barrel 11
at which the lens 12 is installed is inserted into the lens holder
13 to which the adhesive agent is applied.
[0078] In the lens barrel control step (S150) which is, for
example, performed after the reference alignment step (S130) and
the lens barrel insertion step (S140), in order to align the center
of the lens 12 to the reference point P14 of the image sensor 14,
the controller 900 is driven to control the lens barrel 11
according to the lens image. As mentioned above, the lens image is
an image of the test chart 110 detected by the image sensor 14
through the lens 12.
[0079] In the UV curing step (S160), after the center of the lens
12 is aligned to the reference point P14 of the image sensor 14,
the adhesive agent is irradiated with an ultraviolet ray to be
temporarily cured.
[0080] When the camera module 10 is assembled through the
above-mentioned process, the lens barrel coupling tilting is
compensated, and the optical axis between the lens 12 and the image
sensor 14 can be rapidly and accurately aligned.
Adhesive Agent Curing Tilting Correction
[0081] The adhesive agent curing tilting can be caused when the
adhesive agent between the lens holder 13 and the lens barrel 11 is
cured through heating to couple the lens barrel 11 to the lens
holder 13. Due to non-uniformity of a thickness of the cured
adhesive agent, the optical axis of the lens 12 may be
deviated.
[0082] The apparatus and method for aligning the optical axes of
the lenses and assembling the camera module to correct the adhesive
agent curing tilting will be described below with reference to the
relevant drawings.
[0083] The camera module 10 is mounted onto the support block 800.
The camera module 10 includes the substrate 15 at which the image
sensor 14 is installed, the lens barrel 11 at which the lens 12 is
installed, and the lens holder 13 coupled between the substrate 15
and the lens barrel 11.
[0084] The lens holder 13 is fastened to the substrate 15 such that
the active region 14a of the image sensor 14 is exposed through the
holder hole 13a.
[0085] The lens barrel 11 is coupled to the lens holder 13 through
the adhesive agent cured, for example, through heating.
[0086] As shown in FIG. 9, the displacement sensor 200 detects the
tilted state of the lens barrel 11 to generate a barrel tilting
information after the adhesive agent is cured or heated.
[0087] The displacement sensor 200 measures displacement of a
plurality of points 11b on a surface of a predetermined section 11a
of the lens barrel 11 near the displacement sensor 200 to detect
the tilted state of the lens barrel 11.
[0088] The controller 900 is driven to control the support block
800 according to the barrel tilting information to tilt the lens
barrel 11 so as to correct the tilted state of the lens barrel
11.
[0089] As shown in FIG. 10, the vision camera 210 checks the
heating vision image through the lens 12 after the adhesive agent
is cured or heated. Here, the heating vision image is an image of
the lens 12 after the adhesive agent is heated or cured.
[0090] In this case, the controller 900 is driven to shift the
support block 800 (ultimately, the lens 12) or the test chart 110
according to the heating vision image checked by the vision camera
210, so as to match a reference point P12 of the lens and the
reference point P110 of the test chart 110.
[0091] Here, the reference point P12 of the lens 12 is the center
point of the lens 12, and the reference point P110 of the test
chart 110 is the center point of the test chart 110.
[0092] As shown in FIG. 11, the image sensor 14 checks a
determination image through the lens 12 after the adhesive agent is
heated or cured. Here, the determination image is an image of the
test chart 110 detected by the image sensor 14 through the lens 12
after the adhesive agent is heated or cured.
[0093] In this case, the controller 900 determines whether the
optical axis of the camera module 10 is good or bad through the
determination image.
[0094] For example, whether the optical axis of the camera module
10 is good or bad may be determined by comparing the determination
image with a predetermined reference image. In another example,
whether the optical axis of the camera module 10 is good or bad may
be determined by comparing optical axis measurement values of the
determination image with predetermined optical axis reference
values. Or, it may be determined through other various method.
[0095] FIG. 12 is a flowchart showing the method of aligning the
optical axes of the lenses and assembling the module according to
an embodiment of the present invention to perform the adhesive
agent curing tilting correction.
[0096] Referring to FIG. 12, in a module heating step (S205), the
camera module 10 is heated. The camera module 10 includes the
substrate 15 at which the image sensor 14 is installed, the lens
barrel 11 at which the lens 12 is installed, and the lens holder 13
coupled between the substrate 15 and the lens barrel 11. The lens
holder 13 is fastened to the substrate 15 such that the active
region 14a of the image sensor 14 is exposed through the holder
hole 13a, and the lens barrel 11 is coupled to the lens holder 13
through an adhesive agent 2 (referring to FIG. 13A) cured by the
heating.
[0097] Specifically, as shown in FIG. 13A, the dispenser 500 is
driven to apply the adhesive agent 2 to one surface of the lens
holder 13. Then, as shown in FIG. 13B, the lens barrel 11 is
inserted and coupled to an adhesion surface of the lens holder 13.
The operation of inserting the lens barrel 11 into the lens holder
13 may be performed in an automatic or manual manner. The test
chart system 100 is operated such that the test pattern is directly
photographed by the image sensor 14 after the lens barrel 11 is
inserted.
[0098] When it is determined that the optical axes are not properly
aligned upon photographing the test pattern, the lens barrel 11 is
clamped by the lens clamper 300 to be slightly moved on the
coupling surface of the lens holder 13 to adjust a tilting error.
Then, as shown in FIG. 13C, the UV radiator 510 radiates an
ultraviolet ray to primarily or temporarily cure the adhesive agent
2.
[0099] After the lens barrel 11 is coupled as described above, the
surface of the lens 12 is checked with naked eyes by turning on the
LED illuminator 600. The LED illuminator 600 can also perform a
test of the optical axis while checking the surface of the lens 12,
which may have defects such as shading, defects, stains, or the
like.
[0100] The test chart system 100 is operated, and the test pattern
is directly photographed by the image sensor 14.
[0101] After completion of the adjustment, as shown in FIG. 13D,
the camera module 10 is heated by a heater 520 to completely cure
the adhesive agent 2 between the lens holder 13 and the lens barrel
11.
[0102] Referring back to FIG. 12, in a support block setting step
(S210), the heated camera module 10 is set to the support block
800.
[0103] In a barrel tilting correction step (S220), the tilting of
the lens barrel 11 of the heated camera module 10 is corrected. In
the barrel tilting correction step (S220), the plurality of points
11b on the end section 11a of the lens barrel 11 near the
displacement sensor 200 are measured by the displacement sensor 200
to generate barrel tilting information. In order to correct the
tilting of the lens barrel 11, the controller 900 is driven to
control the support block 800 according to the barrel tilting
information.
[0104] In a reference alignment step (S230), in order to match the
reference point P110 of the test chart 110 and the reference point
P12 of the lens 12, the controller 900 is controlled to shift the
support block 800 according to the heating vision image.
[0105] In addition, the reference point P12 of the lens 12 may be
the center point of the lens 12, and the reference point P110 of
the test chart 110 may be the center point of the test chart
110.
[0106] In a determination step (S240), the controller 900
determines whether the optical axis of the camera module 10 is good
or bad through the determination image. For example, the
determination step (S240) may be performed after the reference
alignment step (S230).
[0107] Whether the tilting error of the lens 12 is adjusted by
means of the control of the controller 900 and the lenses are
precisely aligned is checked through the above-mentioned process,
so that the optical axis between the lens 12 and the image sensor
14 can be rapidly and precisely aligned.
[0108] The adhesive agent curing tilting correction may be
performed by a method of aligning optical axes of lenses and
assembling a camera module according to another embodiment of the
present invention.
[0109] Referring to FIG. 14, before heating the camera module 10, a
substrate tilting information generating step (S310) is performed
by measuring a plurality of points on the substrate 15 using the
displacement sensor 200 to generate substrate tilting information.
Here, the camera module 10 includes the substrate 15 at which the
image sensor 14 is installed, the lens barrel 11 at which the lens
12 is installed, and the lens holder 13 coupled between the
substrate 15 and the lens barrel 11. The lens holder 13 is fastened
to the substrate 15 such that the active region 14a of the image
sensor 14 is exposed through the holder hole 13a, and the lens
barrel 11 is coupled to the lens holder 13 through the adhesive
agent 2 cured by the heater.
[0110] In a module heating step (S320), in order to couple the lens
barrel 11 to the lens holder 13 through the adhesive agent 2 cured
by the heater, the camera module 10 is heated.
[0111] In a support block setting step (S330), the heated camera
module 10 is set to the support block 800.
[0112] In to substrate tilting correction step (S340), the
controller 900 is driven to control the support block 800 according
to the substrate tilting information.
[0113] In a determination step (S350), the controller 900
determines whether the optical axis of the camera module 10 is good
or bad through a determination image. Here, the "determination
image" is an image of the test chart 110 detected by the image
sensor 14. For example, the determination step (S350) may be
performed after the substrate tilting correction step (S340).
[0114] Whether the tilting error of the lens 12 is adjusted by
means of the control of the controller 900 and the lenses are
precisely aligned is checked through the above-mentioned process,
so that the optical axis between the lens 12 and the image sensor
14 can be rapidly and precisely aligned.
[0115] The invention has been described with reference to an
exemplary embodiment illustrated in the drawings, but has been
merely exemplified. It will be apparent to those skilled in the art
that various modifications can be made to the above-described
exemplary embodiments of the present invention without departing
from the spirit or scope of the invention. Thus, it is intended
that the present invention covers all such modifications provided
they come within the scope of the appended claims and their
equivalents.
* * * * *